Reflux Still Performance

I have finally had time to build a reflux still which is one of the three allowable units on my Alcohol Fuel Plant permit.  The performance improvement over my old pot still is amazing.  I have standardized my performance testing by using a constant 1500ml of alcohol/water mix containing 75ml of pure alcohol.  I settled on this 5% mixture because it is the best I have been able to do using a corn mash with no added sugar.  Remember, we are making fuel so the cost of refined sugar is out of the question.  Here is the data from my last run:

The initial alcohol potency is over twice that of my old pot still.  For fuel production I would never go back.  It does show, however, that I am still not at the point of being able to create a flammable product in a single step.  I suspect that with more refluxing I will be able to keep increasing the potency of my single distilled product.